1. Field
The exemplary embodiments generally relate to substrate transfer systems and, more particularly, to substrate transfer robots.
2. Brief Description of Related Developments
Conventional substrate processing apparatus may include one or more sections having chambers with an isolated atmosphere (e.g. vacuum or inert gas). Conventional process apparatus may also include a substrate transport system disposed within the isolated atmosphere chambers to transport substrates between the various stations of the processing apparatus. The conventional transport system may include one or more arms and the drive section with motors powering the arms. The motors or parts thereof may be located in the isolated atmosphere, and the conventional drive section may have conventional bearings supporting shafts that power the arms. The conventional bearings may pose a concern for introducing undesired contamination into the isolated atmosphere such as from bearing contact and from the use of lubricants that may off gas for example at vacuum. In addition, conventional drive sections may be located exterior to the walls of the isolated atmosphere or vacuum chambers, with the isolated portion of the drive section in communication with the chambers to effect connection to the arms inside the chambers. Hence, in conventional apparatus the drive section may contribute an additional volume to the isolated atmosphere or vacuum chamber, and corresponding resultant increase in the time for pumping the isolated atmosphere or vacuum in the chamber. Also, the arm sections of conventional transport system may be centrally positioned, in order to effect transport throughout the processing apparatus. Thus, the drive section in conventional systems may be centrally positioned under the bottom of the isolated atmosphere or vacuum chambers thereby restricting or limiting access for connections of other systems to the bottom of the isolated atmosphere chambers. The exemplary embodiments disclosed herein overcome the problems of conventional system as will be described in greater detail below.